A human performance experiment was conducted to investigate pixel parameter requirements for three types of flat-panel display images: an alphanumeric character, an oscilloscope waveform, and a real-world image. Subjects performed similarity judgments between an extremely high-quality image and an image composed of different levels of anti-aliasing and pixel width-plus-pixel separation (pitch). It was found that the effect of pitch had greater influence on perceived image quality for the alphanumeric character and oscilloscope waveform than for the real-world image. The results of this research provide empirical evidence showirg that the pixel pitch requirements for flat-panel systems that are used to display binary, high-contrast images (such as text and waveforms) will be more stringent than for low-contrast pictorial images. The three levels of grey-scale anti-aliasing investigated were found to improve image quality for only the binary, high-contrast images.

No description available.

A novel type of alternating-current (AC) powder electroluminescent (EL) device that relies on nanowire-phosphor heterogeneous junction structure has been developed. It shows promise for manufacturing of highly stable powder EL devices. To pursue this goal, manganese ion (Mn2+)-doped zinc germanate (Zn2GeO4:Mn) oxide phosphor was synthesized and used as EL powder material for the fabrication of the new types of AC powder EL devices. The Zn2GeO4:Mn oxide phosphor powder could eliminate the well-known degradation problem of zinc sulfide (ZnS)-based AC powder EL devices predominant in the current marketplace. In order to realize a high brightness at a relatively low operating voltage, a conductive semiconductor nanowire architecture using zinc oxide (ZnO) and copper oxide (CuO) nanowires with sharp-tip features, was created and integrated into conventional AC powder EL structures. Particularly, vertically-aligned n-type ZnO nanowires arrays were successfully synthesized on a Zn2GeO4:Mn polycrystalline substrate for the first time, and the growth behavior using a chemical vapor deposition (CVD) process was investigated. The density of the ZnO nanowires could be effectively controlled by some experimental parameters, such as the density of gold catalyst nanoparticles, and spatial distance between substrate and CVD source powders. This novel ZnO nanowire-decorated Zn2GeO4:Mn phosphor architecture was used to fabricate top-emission AC powder EL devices. On the other hand, a vertically-aligned ZnO nanowire array was directly synthesized on a thin film indium-tin-oxide (ITO)-coated glass substrate for fabrication of bottom-emission AC powder EL device. The nanowires were adopted to form heterogeneous junction structures between the tips of the nanowires and the Zn2GeO4:Mn EL powders, so that the composites could have a similar electrical field enhancement as in the needle-like CuxS precipitates within widely-used ZnS:Cu EL powder materials. The behavior of these top- and bottom- emission AC powder EL devices was also studied. Alternatively, vertically-aligned p-type CuO nanowires were prepared by a thermal oxidation method. Reliable heterogeneous junction structures were formed by a simple drop-coating method. The CuO nanowire-based AC powder EL device has excellent brightness maintenance with a loss of luminescent intensity under 1 % at over 10 cd/m2 luminance during 360 hours of operation. The integrating of semiconductor nanowires into conventional AC powder EL device structures offers the very promising prospect of fabrication of simple, low-cost, scaled-up EL devices that could fundamentally solve the limited operational lifetime of current ZnS-based AC powder EL devices. / Thesis / Doctor of Philosophy (PhD)

As células eletroquímicas emissoras de luz são dispositivos eletroluminescentes cuja camada ativa é uma mistura de um material eletroluminescente e um eletrólito sólido a base de sais de metais alcalinos, geralmente lítio. A presença dos íons na camada ativa modificam o mecanismo de funcionamento das células quando comparadas ao diodos emissores de luz. Nas células, a concentração de íons nas interfaces eletródicas forma uma dupla camada elétrica que auxilia a injeção de cargas na camada ativa, por sua vez e na presença dos íons, o material eletroluminescente sofre dopagem se tornando condutor, os portadores injetados irão se encontrar numa região da camada ativa recombinando-se e emitindo luz. Compreender as interações dos diversos materiais que formam a camada ativa é fundamental para otimizar o desempenho do dispositivo. Neste trabalho estudamos a interação do ADS108GE, um polímero luminescente, e um eletrólito sólido a base de poli (óxido de etileno) (PEO) e LiCF3SO3 ou LiB(C2O4)2. O LiB(C2O4)2 foi sintetizado neste trabalho para estudar a viabilidade de se substituir o LiCF3SO3 que é o sal tipicamente utilizado nas células. Foram utilizadas técnicas de Análise Dinâmico-Mecânica (DMA), Espectroscopia Vibracional no Infravermelho (FTIR), Microscopia de Força Atômica (AFM), Difração de Raios-X (DRX), Microscopia Óptica de Varredura no Campo Próximo (IR-SNOM), Impedância Elétrica e Voltametria Cíclica. Os resultados de DMA em conjunto com DRX e AFM, permitiram estabelecer que o aumento da concentração de sal contribui para mudanças morfológicas que se relacionam com o aumento da fração de fase amorfa e independem do ânion, demonstrando que estes efeitos estão ligados à interação PEO-Lítio. Por outro lado, os espectros de FTIR e resultados de impedância elétrica mostram que o aumento da concentração de LiCF3SO3 gera agregação do sal diminuindo a condutividade, a mobilidade iônica e o número de portadores efetivos, enquanto para o LiB(C2O4)2 não se observa tal efeito. O IR-SNOM permitiu identificar nas misturas utilizadas como camada ativa que o ADS108GE forma estruturas globulares embebidas numa matriz de PEO. Do ponto de vista operacional, as células a base de LiB(C2O4)2 possuem uma eficiência maior do que as a base LiCF3SO3 e maior estabilidade. / Light-emitting electrochemical cells are electroluminescent devices whose active layer is a mixture of an electroluminescent material and a solid electrolyte based on alkaline salts, usually a lithium salt. The ions within thea ctive layer change the devices working mechanism when compared to light emitting diodes. In the cells, there is an ion build up at electrodic interfaces creating an electric double layer allowing charge injection in the active layer. The electroluminescent material is doped by these injected charges becoming conductive. These injected charges recombine emitting light. In order to optimize devices performance, it is fundamental to study materials interactions when mixed as an active layer. In this work, we studied the interactions between ADS108GE, a luminescent polymer, and a solid electrolyte based on polyethylene oxide and LiCF3SO3 or LiB(C2O4)2. LiB(C2O4)2 was prepared in this work to assess its feasibility as LiCF3SO3 substitution which is the typical choice. We used the following techniques in this work: Dynamical Mechanical Analysis (DMA), Infrared Vibration Spectroscopy (FTIR), Atomic Force Microscopy AFM), X-Ray Diffraction (XRD), Infrared Scanning Near-Field Optical Microscopy (IRSNOM), Electrical Impedance and Cyclic Voltammetry. From DMA, XRD and AFM results, it is possible to conclude that as we increase salt concentration, the active layer has morphological changes related to an increasing fraction of an amorphous phase. These effects are anion independent showing that PEO-Li interactions are the responsible ones. On the other hand, FITR and electrical impedance experiments show that increasing LiCF3SO3 concentration leads to salt aggregation decreasing conductivity, ionic mobility and the effective number of carriers, moreover, we do not see this effect with LiB(C2O4)2. IR-SNOM identified that ADS108GE were organized as globular structures embedded in a PEO matrix. The cells made with LiB(C2O4)2 were more efficient than those based on LiCF3SO3 and were even more stable.

Complexos contendo íons de terras raras são de grande interesse na fabricação de dispositivos eletroluminescentes como é o caso do diodo emissor de luz construído com compostos orgânicos (OLED). Esses dispositivos, utilizando íons de terras raras trivalentes (TR3+) como centros emissores, exibem alta luminescência com bandas espectrais extremamente finas devido à estrutura dos seus níveis de energia, tempos de vida longos e a alta eficiência quântica. Este trabalho relata a preparação de complexos de β-dicetonatos (tta - tenoiltrifluoroacetonato e acac - acetilacetonato) de terras raras (Tb3+, Eu3+ e Gd3+) contendo ligante macrocíclico éter coroa (DB18C6 - dibenzo18coroa6) e de filmes poliméricos de UO22+. Os materiais obtidos foram caracterizados por titulação complexométrica com EDTA, análise elementar de CH, espectroscopia de absorção na região do infravermelho, análise termogravimétrica, difratometria de raios X (método do pó) e espectroscopia de luminescência. Na manufatura do dispositivo OLED construído neste trabalho utilizou-se a técnica de deposição física de filmes finos por fase vapor (PVD, Physical Vapor Deposition). / Complexes containing Rare Earth ions are of great interest in the manufacture of electroluminescent devices as organic light emitting devices (OLED). These devices, using rare earth trivalent ions (TR3+) as emitting centers, show high luminescence with extremely fine spectral bands due to the structure of their energy levels, long life time and high quantum efficiency. This work reports the preparation of Rare Earth β-diketonate complexes (Tb3+, Eu3+, Gd3+) and (tta - tenoyltrifluoroacetonate and acac - acetylacetonate) containing a ligand macrocyclic crown ether (DB18C6 - dibenzo18coroa6) and polymer films of UO22+. The materials were characterized by complexometric titration with EDTA, CH elemental analysis, near infrared absorption spectroscopy, thermal analysis, X-ray diffraction (powder method) and luminescence spectroscopy. For manufacturing the OLED it was used the technique of deposition of thin films by physical vapor (PVD, Physical Vapor Deposition).

Lo Loc Ping = 多體量子系統問題 / 盧樂平. / Thesis submitted in: October 2004. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 168-171). / Text in English; abstracts in English and Chinese. / Lo Loc Ping = Duo ti liang zi xi tong wen ti / Lu Leping. / Abstract --- p.i / 摘要 --- p.ii / Acknowledgment --- p.iii / Chapter I --- Computational Quantum Mechanics and Its Applications 電算量子力學及其應用 --- p.1 / Chapter 1 --- An Overview of Quantum Mechanics and Some Important Tools of Theory --- p.2 / Chapter 1.1 --- The Schrodinger Equation --- p.2 / Chapter 1.2 --- The Variational Method --- p.4 / Chapter 1.2.1 --- Rayleigh-Ritz Approach --- p.4 / Chapter 1.2.2 --- Linear Variation --- p.5 / Chapter 2 --- Theoretical Methodology of Electronic Structures: Ab Initio Molecular Orbital Theory --- p.7 / Chapter 2.1 --- The Molecular Hamiltonian --- p.7 / Chapter 2.2 --- Hartree Description and Linear Combination of Atomic Orbitals Expan- sion --- p.8 / Chapter 2.3 --- Slater Determinant and the Pauli Exclusion Principle --- p.9 / Chapter 2.4 --- The Expansion of E in Terms of Integrals over MOs --- p.11 / Chapter 2.5 --- Derivation of the Hartree´ؤFock Equations --- p.15 / Chapter 2.6 --- The Self-Consistent Field Calculation --- p.18 / Chapter 2.7 --- Koopmans' Theorem --- p.19 / Chapter 2.8 --- Orbital and the Total SCF Electronic Energy --- p.20 / Chapter 2.9 --- AO Basic Sets --- p.21 / Chapter 2.9.1 --- Slater-Type Orbitals --- p.21 / Chapter 2.9.2 --- Gaussian Functions --- p.22 / Chapter 2.10 --- The Hartree-Fock Limit --- p.23 / Chapter 2.11 --- Electron Correlation --- p.23 / Chapter 2.11.1 --- Weakness in the Single Determinant Model --- p.23 / Chapter 2.11.2 --- Configuration Interaction --- p.24 / Chapter 2.11.3 --- The Coupled-Cluster Method --- p.25 / Chapter 2.11.4 --- Density Functional Theory --- p.26 / Chapter 2.12 --- Frontier Orbitals --- p.31 / Chapter 3 --- Theoretical Investigation of the Interaction between Metal and Tris(8- hydroxyquinoline) aluminum in Organic Light Emitting Diodes --- p.32 / Chapter 3.1 --- Organic Light Emitting Diodes and Tris(8-hydro-xyquinoline) aluminum --- p.32 / Chapter 3.2 --- Computational Methodology --- p.33 / Chapter 3.3 --- Alq3 --- p.34 / Chapter 3.3.1 --- Molecular Structure --- p.34 / Chapter 3.3.2 --- Electronic Structure --- p.36 / Chapter 3.3.3 --- Transition and Relaxation Energies --- p.44 / Chapter 3.3.4 --- Interactions with Metals --- p.45 / Chapter 3.4 --- "Li-Alq3, Na-Alq3 and K-Alq3 Complexes" --- p.46 / Chapter 3.4.1 --- Molecular Structure --- p.46 / Chapter 3.4.2 --- Ground-State Electronic Structure --- p.55 / Chapter 3.4.3 --- Transition and Relaxation Energies --- p.67 / Chapter 3.5 --- "Be-Alq3, Mg´ؤAlq3 and Ca´ؤAlq3 Complexes" --- p.68 / Chapter 3.5.1 --- Molecular Structure --- p.68 / Chapter 3.5.2 --- Ground-State Electronic Structure --- p.76 / Chapter 3.5.3 --- Transition and Relaxation Energies --- p.87 / Chapter 3.6 --- "B-Alq3, Al-Alq3 and Ga-Alq3 Complexes" --- p.87 / Chapter 3.6.1 --- Molecular Structure --- p.87 / Chapter 3.6.2 --- Ground-State Electronic Structure --- p.95 / Chapter 3.6.3 --- Transition and Relaxation Energies --- p.106 / Chapter II --- Analytical Studies of Polarons and the Electron-Phonon Interaction 極子與電子一聲子相互作用的 解析研究 --- p.107 / Chapter 4 --- Optimal Coupled-Cluster Approximation of the Ground-State Energy of the E× (α1 + α1) Jahn-Teller System --- p.108 / Chapter 4.1 --- The Jahn-Teller Effect --- p.108 / Chapter 4.2 --- Approximation in the Coupled-Cluster Method and the Jahn-Teller Hamiltonian --- p.110 / Chapter 4.3 --- Variational Coupled-Cluster Approximation --- p.112 / Chapter 4.3.1 --- The Zeroth Level --- p.113 / Chapter 4.3.2 --- The First Level --- p.113 / Chapter 4.3.3 --- The Second and the Third Levels --- p.114 / Chapter 4.4 --- An 'Optimal' Hamiltonian --- p.115 / Chapter 4.5 --- Treatment for the k> 1 Case --- p.117 / Chapter 4.6 --- Energies and Other Physical Phenomena --- p.118 / Chapter 5 --- Small-to-Large Ground-State Polaron Crossover in One-Dimension Extended E×e Jahn-Teller System Using Variational Coupled-Cluster Approximation --- p.134 / Chapter 5.1 --- Polaron Formation --- p.134 / Chapter 5.2 --- Model Hamiltonian and the MLF Transformation --- p.135 / Chapter 5.3 --- Variatonal Coupled-Cluster Approximation --- p.137 / Chapter 5.3.1 --- Zeorth Level --- p.139 / Chapter 5.3.2 --- First Level --- p.139 / Chapter 5.3.3 --- Second Level --- p.142 / Chapter 5.4 --- Energies and Static Correlation Functions --- p.142 / Chapter 5.5 --- Approximate Form of the MLF Transformation for K = 0 --- p.153 / Chapter 5.5.1 --- Zeroth Level --- p.154 / Chapter 5.5.2 --- First Level --- p.155 / Chapter 5.5.3 --- Second Level --- p.156 / Chapter 5.5.4 --- Energies and Static Correlation Functions --- p.157 / Chapter 5.6 --- Synopsis --- p.167 / Bibliography --- p.171

Complexos contendo íons de terras raras são de grande interesse na fabricação de dispositivos eletroluminescentes como é o caso do diodo emissor de luz construído com compostos orgânicos (OLED). Esses dispositivos, utilizando íons de terras raras trivalentes (TR3+) como centros emissores, exibem alta luminescência com bandas espectrais extremamente finas devido à estrutura dos seus níveis de energia, tempos de vida longos e a alta eficiência quântica. Este trabalho relata a preparação de complexos de β-dicetonatos (tta - tenoiltrifluoroacetonato e acac - acetilacetonato) de terras raras (Tb3+, Eu3+ e Gd3+) contendo ligante macrocíclico éter coroa (DB18C6 - dibenzo18coroa6) e de filmes poliméricos de UO22+. Os materiais obtidos foram caracterizados por titulação complexométrica com EDTA, análise elementar de CH, espectroscopia de absorção na região do infravermelho, análise termogravimétrica, difratometria de raios X (método do pó) e espectroscopia de luminescência. Na manufatura do dispositivo OLED construído neste trabalho utilizou-se a técnica de deposição física de filmes finos por fase vapor (PVD, Physical Vapor Deposition). / Complexes containing Rare Earth ions are of great interest in the manufacture of electroluminescent devices as organic light emitting devices (OLED). These devices, using rare earth trivalent ions (TR3+) as emitting centers, show high luminescence with extremely fine spectral bands due to the structure of their energy levels, long life time and high quantum efficiency. This work reports the preparation of Rare Earth β-diketonate complexes (Tb3+, Eu3+, Gd3+) and (tta - tenoyltrifluoroacetonate and acac - acetylacetonate) containing a ligand macrocyclic crown ether (DB18C6 - dibenzo18coroa6) and polymer films of UO22+. The materials were characterized by complexometric titration with EDTA, CH elemental analysis, near infrared absorption spectroscopy, thermal analysis, X-ray diffraction (powder method) and luminescence spectroscopy. For manufacturing the OLED it was used the technique of deposition of thin films by physical vapor (PVD, Physical Vapor Deposition).

New textile materials are constantly being brought into the automotive field, and automobile design is a leader in innovative and spectacular developments where smart textile materials are used. The main elements of the current project are textile material research, automotive research, design and development of two upholstery concepts for automotives using smart textiles. The added values are RFI/EMI (Radio Frequency Interference / Electro Magnetic Interference) shielding qualities, light emitting, light reflective and antistatic qualities. Values in the smart-textile area are obtained through choice of material and textile techniques. Transportation textiles are considered high performance technical fabrics, but they must also meet the aesthetic demands of the market. In the current project the design is inspired by Japanese architectural thinking and strives to relate to outdoor environment to reduce the border between indoor and outdoor environment. The inspiration source is water surfaces. The colour setting is also inspired by water surfaces. Material selection is based on the chosen added values, material qualities, appearance and availability. The result of the work is two different upholstery concepts visualizing qualities of smart materials and requests the automotive field. Sprinkle is an upholstery with light emitting, light reflective and antistatic values. The materials used are monofilament, polyester and electroluminescent wires. Wave is an upholstery design with antistatic, light reflective and RFI/Emi shielding qualities. The materials used are stainless steel yarn, rubco and monofilament. / <p>Program: Konstnärligt masterprogram i mode- och textildesign</p><p>Uppsatsnivå: D</p>

by Xu Mingsheng. / "October 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

Orientador: Giovani Fornereto Gozzi / Resumo: Dispositivos Eletroluminescentes (EL) são comumente utilizados para iluminação ambiente e transmissão visual de informações, possuem uma enorme gama de aplicações em setores diversos, como para tratamento fototerápico e decoração. Entre as atuais tecnologias, os dispositivos produzidos com compósitos eletroluminescentes têm potencial de emprego em aplicações emergentes devido ao seu baixo custo, flexibilidade mecânica e escalabilidade. Estas vantagens tecnológicas estão atreladas ao fato destes dispositivos poderem ser produzidos utilizando-se técnicas de impressão gráfica, como por exemplo, a técnica de impressão serigráfica. Neste sentido, este trabalho tem como objetivo o desenvolvimento de dispositivos EL totalmente impressos utilizando a técnica de impressão serigráfica. Para tanto, a pasta condutora transparente (PCT) e a pasta de prata (PTF), ambas fornecidas pela empresa TICON, foram utilizadas para a produção de eletrodos transparentes e opacos, respectivamente. A camada ativa dos dispositivos foi produzida com o compósito eletroluminescente (PEL), o qual foi desenvolvido durante o presente estudo. Filmes dos materiais PCT, PEL e PTF foram depositados utilizando-se telas com diversas lineaturas e caracterizados com relação às suas propriedades morfológicas, elétricas e ópticas, com a finalidade de identificar as melhores lineaturas de telas serigráficas para o processamento de cada um dos materiais. Por fim, dispositivos EL do tipo LECEL (Light-Emitting Composite Ele... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Electroluminescent (EL) devices have a wide range of applications. Among current technologies, devices produced with electroluminescent composites have potential for use in emerging applications due to their low cost, flexibility and scalability. Scalability and cost-effectiveness are characteristics also related to device processing methods, amongst which printing techniques, such as screen-printing, are the most appropriated to achieve these goals. Therefore, this research regards on development of screen-printed EL devices. For this purpose, the transparent conductive paste (PCT) and the silver paste (PTF), both sourced by TICON, were used for transparent and opaque electrodes fabrication, respectively. The active layer of the devices have been produced with an electroluminescent composite (PEL) developed during the present study. We have produced screen-printed films with the PCT, PEL and PTF materials using screens with different mesh counts to study the influence of mesh count on the morphological, electrical and optical properties of the films. In addition, we have performed a study regarding the influence of mesh count on the EL device performance parameters. As main result, we have fabricated a screen-printed EL device, using screens with appropriated mesh counts for deposition of each material, which exhibited luminance of 50 cd/m2 (at 110 V) and turn-on voltage of (18 ± 2) V. / Mestre